Sliver tension equalizer



March 29, 1966 G. e. FORNES SLIVER TENSION EQUALIZER Filed 001;. 4, 1963 INVENTOR Gasron G. Fornes BY M M 770927! 7% 4 4 44: ATTORNEYS United States Patent 3,242,534 SLTVER TENSION EQUALKZER Gaston G. Fornes, Charlottesville, Va., assignor to Institute of Textile Technology Filed Oct. 4, 1963, Ser. No. 314,056 4 Claims. (Cl. 19-159) This invention relates to and is to be used in connection with a sliver packing apparatus in which the coiler head is movable. The invention particularly relates to a mechanism for guiding and maintaining a constant tension upon the sliver being introduced into the coiler head as the coiler head moves along a vertical axis.

Sliver is a composite of textile fibers arranged in a rope-like mass having a substantially circular cross-section. After the individual fibers have been cleaned and straightened in a carding machine, they are combined as they leave the machine to form the sliver. It is customary at this stage to pack the sliver into cans .OI drums. At a later stage in the manufacture of yarn, several slivers may be combined in a drawing frame and the sliver thus formed is also packed in cans.

Sliver is packed by means of a sliver packing apparatus. The principal element of such an apparatus is the coiler head, which is designed to pull the sliver into the coiler head and deposit the sliver in a series of coils. Conventionally, the coiler head is disposed above the sliver can in a fixed position.

A sliver packing apparatus having a movable coiler head is described in co-pending Robinson et al. application Serial No. 284,693 of which the present applicant is a co-inventor. The apparatus there described is for a sliver packing apparatus having a vertically movable coiler head which may be introduced into an empty sliver can to a point near the bottom of the can. As sliver is introduced into the can via the coiler head, the coiler head presses against the sliver coils. As the coils are successively deposited in the can, thereby building a sliver pack, the coiler head is caused to move upwardly while maintaining constant pressure contact with each coil as it is deposited. The use of such a sliver packing apparatus enables greater and more uniform amounts of sliver to be packed into a sliver can.

The present invention has particular application to a sliver packing apparatus having a movable coiler head as described in the above mentioned Robinson et al. application. In the packing process, the sliver is passed directly from the carding machine or from a drawing frame to the coiler head. The sliver exits from the carding machine or drawing frame at a uniform rate and is pulled through the coiler head at a uniform rate. Because of the sliver connection between the coiler head of the sliver packing apparatus and the machine forming the sliver, any movement of the coiler head will necessarily vary the tension upon the sliver. Thus, in a situation where the coiler head moves along a vertical axis, the up and down movement of the coiler head would tend to increase or decrease the tension upon the sliver depending upon the original length of sliver and the relative positions of the mechanisms. For example, should sliver be initially threaded into the coiler head when the head is positioned above a sliver can, a downward movement of the coiler head into the can would stretch or even break the sliver.

The present invention is based upon the discovery that tension may be equalized and a uniform tension maintained upon the sliver during the vertical movements of the coiler head by means of a specially designed tension control frame and a counterbalanced stepped differential drum. Based upon this discovery the present invention is for a mechanism for equalizing tension upon the sliver entering the coiler head which mechanism comprises a 3,242,534 Patented Mar. 29, 1966 tension control frame and a counterbalanced stepped differential drum. A flexible lifting means connects the tension control frame with the stepped differential drum and a flexible drum rotation means connects the movable coiler head to the stepped differential drum, whereby movement of the coiler head causes a corresponding movement of the tension control frame.

A better understanding of the invention will be had by reference to the drawing which shows the elements of the invention as used in connection with a movable coiler head.

Referring to the drawing, the tension control frame is enoted generally as 1. In the preferred embodiment of the invention shown, tension control frame 1 has a frame support 2 and guide pulleys 3 and 4. The frame 1 is also preferably equipped with a sliver trough 5. Frame 1 is movable along a vertical axis and is prevented from lateral movement by guide rods 6 and 7 slidable through ball bushing sleeves 8 and 9, respectively. Ball bushing sleeves 8 and 9 are in turn mounted upon a fixed support 10. Fixed support 10 is in turn held by rods 19 connected to support table 16. Bridging the top of guide rods 6 and 7 is a bar stop 11 which limits the downward travel of frame 1.

Disposed above the tension control frame 1 is a stepped differential drum denoted generally as 12. The stepped differential drum 12 comprises a major drum 13 and a minor drum 14. Major drum 13 and minor drum 14 are concentric and are keyed to a common axis 15 which is in turn mounted upon support table 16. Thus, the movement of one drum causes the other drum to move along with it at the same rotational speed. In the preferred embodiment of the invention the major drum 13 has a pitch diameter twice that of the minor drum 14 for reasons to be discussed later. A flexible lifting means, preferably a chain 17, connects the tension control frame 1 to the minor drum 14. As the minor drum 14 rotates clockwise, the chain 17 is wound up upon the minor drum and engages peripheral sprocket teeth 18. Thus, clockwise rotation of the drums causes tension control frame 1 to be raised. Conversely, counterclockwise rotation lowers the frame.

The principal elements of the sliver packing apparatus are shown. They are the coiler head denoted generally as 20, having calender rolls 21 and 22, sliver condensing trumpet 23, and tube gear 24. The coiler head 20 is movable vertically and is kept from lateral movements by guide columns 25 and 26 slidable through collars 27 and 28. The raising and lowering of the coiler head 20 is preferably by means of a pneumatic piston device 29 having a rod portion 30 attached to a brace 31 connected atop guide columns 25 and 26.

The source of power of the pneumatic piston device 29 is not shown and the operation of the sliver packing apparatus will not be described in detail. However, as shown in the drawing, the coiler head 20 is in a lowered position as it might be within a sliver can (not shown) near the start of the packing operation. As sliver builds up in the sliver can, the coiler head 20 rises to the position shown by the dotted lines. When the can becomes filled, the can is doffed, an empty can is placed into position below the coiler head, and the coiler head is lowered into the can, thus completing the cycle.

A flexible tension means, preferably a tension chain 33, connects the brace 31 with the major drum 13. The chain 33 preferably passes over a guide sprocket Wheel 34, connected to support table 16, and engages peripheral sprocket teeth 35 of the major drum 13. Chain 33 is wound upon drum 13 when drum 13 is rotated clockwise. Also operatively connected with major drum 13 is a counterweight 36. counterweight 36 is dependently connected to the drum 13 by a cable 37 which passes over a wound up or paid out in constant relative lengths.

pulley 38 mounted upon support table 16. Cable 37 is wound up on drum 13 when the drum 13 is rotated counterclockwise.

It can be seen that a downward movement of the coiler head 20 will act through chain 33 to cause the stepped differential drum 12 to rotate counterclockwise, while an upward movement of the coiler head 20 will allow the counterweight 36 to act through cable 37 to cause the stepped differential drum 12 to rotate clockwise. Thus, depending upon the movement of the coiler head 20, chain 33 and cable 37 will alternately act as a drum rotation means for rotating the differential drum responsively to the movements of the coiler head 20.

Sliver 39' is shown as it exits from a drawing frame (not shown) through a trumpet 40 and driven rollers 41 and 42. It thereupon passes over guide pulley 4, through sliver trough 5, over guide pulley 3 and into sliver condensing trumpet 23. The sliver 39 is then pulled by calender ro-lls 21 and 22 into the tube gear 24 and exits at the bottom of the coiler head for depositing into a sliver can.

The operation of the sliver tension equalizer is as follows. As the coiler head 20 is raised, either by the action of the pneumatic piston assembly 29 or by the pressure of a growing sliver pack, the distance between the coiler head 20 and the rolls 41 and 42 decreases, thereby tending to slacken the sliver 39 between those points. This decrease or slackening can be expressed in terms of the vertical distance traveled by the coiler head, It. Because the sliver 39 is looped over guide pulley 4, an upward movement of the tension control frame 1 and guide pulley 4 by a distance V: It will exactly compensate for the apparent decrease in tension. Thus, tension will be equalized and a constant tension will be maintained upon the sliver 39. Conversely, a downward movement of the coiler head 20 will tend to stretch the sliver 39. A corresponding downward movement of the tension control frame 1 by one-half the distance moved by the coiler head 20 will exactly compensate for any change in tension needed to maintain constant tension in the sliver 39.

The means used to cause the tension control frame 1 to respond the proper amount to every movement of the coiler head 20 is the stepped differential drum 12. As noted above, the major drum 13 has a pitch diameter twice that of the minor drum 14. Thus, as the stepped differential drum 12 is rotated, the chains 17 and 33 are For example, as stepped differential drum 12 is rotated clockwise a length h of chain 33 will be wound up on drum 13 while a length /2 h of chain 17 will be wound up on drum 14. Because of the connections of chain 33 with the coi-ler head 20 and of chain 17 with the tension control frame 1 the movement of coiler head 20 by a distance h will always result in a corresponding movement of the tension control frame /2 h in the same direction.

The forces acting upon the stepped differential drum 12 causing it to rotate are directed by the movement of the coiler head 20. The positive force causing the drum 12 to rotate counterclockwise is generated by the pneumatic piston 29 when it drives the coiler head 20 down into a sliver can. The upward movement of the coiler head 20 permits the counterweight 36 to act upon the drum 12 via cable 37, thus causing a clockwise rotation of the drum.

In addition to performing the function of sliver tension equalization, it can be seen that the embodiment shown in the drawing permits the orderly introduction of sliver into sliver cans. In the absence of such a device the up and down movements of the coiler head 20 would lead to snarling of the sliver 39 as the sliver is alternately slackened and tightened. The use of pulleys 3 and 4 and of sliver trough directs the sliver 39 into the coiler head 20 in an orderly manner over a substantially constant course.

Modifications of the embodiment shown may be made within the scope of the invention. For example, the stepped differential drum 12 may be counterbalanced by other means than the counterweight 36, such as a spring means.

Also, the tension control frame 1 might have but one pulley, or merely a sliver trough.

I claim: 1. In a sliver packing apparatus having a movable coiler head, a mechanism for equalizing tension upon the sliver entering the coiler head, which mechanism comprises (a) a tension control frame adapted to support the sliver, (b) a rotatable stepped differential drum the stepped portions thereof being major and minor diameter drums, said stepped drum being spaced from the tension control frame, (c) lifting means connecting the tension control frame to the minor diameter drum of said stepped differential drum, and (d) means for rotating the differential drum responsively to the movements of the coiler head whereby the tension control frame is correspondingly raised and lowered, such rotating means including connecting means between the coiler head and the major diameter drum, and means for urging the differential drum into rotation such that the frame is lifted when the coiler head rises. 2. In a sliver packing apparatus having a movable coiler head, a mechanism for equalizing tension upon the sliver entering the coiler head, which mechanism comprises (a) a tension control frame adapted to support the sliver, (b) a rotatable stepped differential drum disposed above the tension control frame and comprising a major drum and a minor drum, (c) a flexible lifting means connecting the tension con trol frame to the minor drum and windab-le thereon, and (d) means for rotating the differential drum responsively to the movements of the coiler head, such means comprising (i) a flexible means connectin the coiler head to the major drum for rotating the differential drum in one direction, and (ii) a means for urging the differential drum into rotation in the opposite direction. 3. In a sliver packing apparatus having a movable coiler head, a mechanism for equalizing tension upon the sliver entering the coiler head, which mechanism comprises (a) a tension control frame having a sliver guide means adapted to support the sliver, (b) a rotatabe stepped differential drum disposed above the tension control frame and comprising (i) a major drum having a major diameter, and (ii) a concentric minor drum having a minor diameter one-half of said major diameter, (c) a flexible lifting means connecting the tension control frame to the minor drum, and windable thereon, (d) means for rotating the differential drum responsively to the movement of the coiler head comprising (i) a flexible means connecting the coiler head to the major drum for rotating the difl'erential drum in one direction, and (ii) a counterbalance for rotating the differential drum in the opposite direction. 4. In a sliver packing apparatus having a movable coiler head, a mechanism for equalizing tension upon the sliver entering the coiler head, which mechanism comprises (a) a tension control frame having a sliver guide pulley adapted to support the sliver, (b) a rotatable stepped differential drum disposed above the tension control frame comprising (i) a major drum having (a) peripheral teeth, and (b) a major pitch diameter,

(ii) a concentric minor drum having (a) peripheral teeth, and

and engaging the peripheral teeth of the major drum, and

(e) a counterweight dependently connected by a cable to the major drum and the cable being windable upon the major drum in a direction opposite that of the chains.

No references cited.

10 DONALD W. PARKER, Primary Examiner.

D. NEWTON, Assistant Examiner. 

1. IN A SLIVER PACKING APPARATUS HAVING A MOVABLE COILER HEAD, A MECHANISM FOR EQUALIZING TENSION UPON THE SLIVER ENTERING THE COILER HEAD, WHICH MECHANISM COMPRISES (A) A TENSION CONTROL FRAME ADAPTED TO SUPPORT THE SLIVER, (B) A ROTATABLE STEPPED DIFFERENTIAL DRUM THE STEPPED PORTIONS THEREOF BEING MAJOR AND MINOR DIAMETER DRUMS, SAID STEPPED DRUM BEING SPACED FROM THE TENSION CONTROL FRAME, (C) LIFTING MEANS CONNECTING THE TENSION CONTROL FRAME TO THE MINOR DIAMETER DRUM OF SAID STEPPED DIFFERENTIAL DRUM, AND (D) MEANS FOR ROTATING THE DIFFERENTIAL DRUM RESPONSIVELY TO THE MOVEMENTS OF THE COILER HEAD WHEREBY THE TENSION CONTROL FRAME IS CORRESPONDINGLY RAISED AND LOWERED, SUCH ROTATING MEANS INCLUDING CONNECTING MEANS BETWEEN THE COILER HEAD AND THE MAJOR DIAMETER DRUM, AND MEANS FOR URGING THE DIFFERENTIAL DRUM INTO ROTATIONS SUCH THAT THE FRAME IS LIFTED WHEN THE COILER HEAD RISES. 